Method of heating an electrical and thermal nonconductor



July 7, 1931. E. E. ROSAIRE 1,813,425

METHOD OF HEATING AN ELECTRICAL AND THERMAL NONCONDUCTOR Filed May 22,192

Mme/#05 591/1945 Ram/m iatentecl July 1931 UNlTED STATES rarsm orricsESME EUGENE ROSAIRE, OF HOUSTON, TEXAS, ASSIGNOR TO WESTERN ELECTRICCOM- PANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORKMETHOD OF HEATING AN ELECTRICAL AND THERMAL NONCONDUCTOR Applicationfiled May 22,

This invention relates to a method of heating an electrical and thermalnon-conductor and is especially well adapted to any process in which itis desirable to heat non-conductors as in baking, vulcanizing, fusing,etc.

The object of the invention is to provide a method for uniformly heatingan electrical and thermal non-conductor by generating heat in theinterior and throughout the entire mass of the non-conductor.

In practicing the invention, a quantity of electrically conductingparticles is incorporated in a non-conducting or insulating material,and the article or body containing the electrically conducting particlesis then sub jected to an alternating magnetic field produced by a highfrequency oscillating current. The variation of the magnetic fieldinduces eddy currents in the conducting particles and causes them tobecome heated. By

uniformly distributing these particles a uniform heating may beobtained.

A better understandingofthe invention may be had from the followingdescription, taken in conjunction with the accompanying drawing whichillustrates one embodimeiit of the invention.

The drawing illustrates the application of the invention to the basingof a vacuum tube having a bulb 1 and a base 2 which are held together bya cementing material 3. A quantity of conducting particles such ascopper or aluminum are incorporated in the cementing material for thepurpose of baking the ce- 5 menting material when the conductingparticles become heated through the influence of the alternatingmagnetic field.

The alternating magnetic field is produced by a coil 6, which forms partof an oscillat- 0 ing circuit 4, 5, 6, 7 and 8 of any suitable type.

The operation of the oscillating circuit is well understood by thoseskilled in the art and will not be described in detail since it forms nopart of this invention.

The tube is based in the following manner: The bulb is placed in aninverted position and the wires 8 are threaded through openings formedin the base. A ring of cement consisting of a mixture of silica andshellac and containing a quantity of conducting particles 1926. SerialNo. 110,891.

uniformly dispersed therethrough is applied just above the shoulder ofthe tube. In the same manner a small quantity of the cement is appliedto the inside of the base. The base is then pressed firmly against theglass and the wires protruding through the base are bent over sharply soas to hold the base securely in position. Keeping the tube in theinverted position it is subjected to the influence of the coil 6 and thetemperature of the cementing material is raised to about 100 C. and heldat that temperature for approximately two hours. At this time a firmbond has been formed between the cement and the adjacent material. Thetube is removed from the coil and the wires 8 are soldered to contacts(not shown) to complete the tube.

By employing this method the bulb and the base of the tube are notappreciably heated as is the case when the cementing material is bakedin an oven according to one practice followed in the manufacture ofvacuum tubes.

It will be understood that the application of the method hereindescribed and illustrated is merely a convenient and useful form of theinvention, which is capable of many other applications without departingfrom i the spirit and scope of the invention.

What is claimed is:

1. The method of heating an electrical and thermal non-conducting, body,which consists in incorporating particles of conducting material in thenon-conducting body and then subjecting the body to the influence of analternating magnetic field.

2. The method of heating a non-conducting material, which consists inmixing conducting particles with the non-conducting material andinductively heating the conducting particles.

3. The method of heating a mixture of conducting and non-conductingmaterials, which consists in subjecting the mixture to an alternatingmagnetic field and heating the materials by the eddy currents induced inthe conducting material by the magnetic field.

4. The method of basing a vacuum tube, which consists in incorporatingconducting particles in a cementing material, applying the cementingmaterial between the bulb and the base, and inductively baking thecementing material.

5. The method of basing a vacuum tube by applying a, mixture ofcementing material and conducting particles between the bulb and thebase, and inductively baking the mixture.

6. The method of basing a vacuum tube,

- which consists in applying a cementing material between the bulb andthe base and inductively generating heat within the cementin material tobake the latter. v I

The method of heat treating a composition of matter which comprisesincluding in the composition a metallic conductor and subj ecting thesame to high frequency induction heating. v

8. The method of securing one body to another by a cement having as partthereof a 1 conductive material which consists in baking the material byhigh frequency induction heating.

9. The method of securing a bulb to a nonconductive base which comprisesemploying a cement containing a conductor, positioning the cement incontact with and intermediate the bulb and base, and baking the cementby high frequency induction heating.

10. The method of uniting non-conductive bodies by a cement whichcomprises incororating in the cement a material capable of being bakedby high frequency induction heating and in disposing the cement whenbetween the bodies in a high frequency field.

11. The method of manufacturing an electrical device having an evacuatedenvelope and a base, which comprises disposing a conductive adhesivematerial between the base and envelope and in baking the said materialby high frequency induction heating.

12. The method of securing amass of material of poor heat conductivityto'a glass article which consists in interposing between said articleand said mass a layer of basing cement in intimate thermal relation withmetal and baking said cement by heat localized at said metal and appliedotherwise than by conduction throu h said mass.

13. The method o afiixing to a glass bulb a base composed of material ofpoor heat conductivity which consists in interposing between the bulband the base a layer of cement adjoining metal and developing in saidmetal sufiicient heat to bake said cement.

In witness whereof, I hereunto subscribe my name this 7th day of May, A.D. 1926.

ESME EUGENE ROSAIRE.

